Experimental Study of Non-thermal Plasma Injection System Converting NOx in Simulated Diesel Emissions

In order to study the removal effect of non-thermal plasma (NTP) after-treatment system on diesel engine harmful emissions, a dielectric barrier discharge (DBD) plasma reactor is designed, and the NOx removal effect is studied under the conditions of different NTP injected gas flow rates and simulated diesel engine exhaust gas temperatures using a NTP injection system which is located outside the diesel engine exhaust pipe. The results show that the injection system can play an effective role in dealing with the harmful emissions of diesel engines; in NTP environment, conversion of NO to NO₂ is the main reaction; with increasing the peak-to-peak applied voltage, NO conversion rate first rises and then falls; correspondingly, when the flow rates of simulated diesel engine exhaust gas are different, the flow rates of NTP injected gas are various, there is an optimum value which lead to the maximum conversion rate of NO; high temperature goes against the NO conversion.